The present disclosure generally relates to in vitro diagnostics devices for automatically removing closures from sample tubes and, in particular, to a decapping/recapping device for removing closures from sample tubes and for reclosing the same tubes with the same respective closures. The present disclosure also refers to a pipetting system and to an analytical system comprising the decapping/recapping device.
Coming from diverse healthcare facilities, biological samples such as blood samples usually arrive in the laboratories in different kinds of sample tubes with various closures. These are called primary sample tubes because they are used to collect the samples, e.g., by venipuncture.
There are instruments, which may process primary sample tubes without the need to remove the closure, i.e., by accessing the sample contained in the primary tube by piercing the closure with, for example, a pipetting needle. Not all closures are however suitable for this procedure and not all types of instruments and/or analysis allow this type of procedure. Some types of instruments and/or analysis require the primary tubes to be opened before samples are pretreated and/or analyzed. Therefore, such instruments should have an automatic decapper to automatically remove the closure from a primary tube.
Automating decapping of test tubes is complicated by the variety of available test tubes, which may vary in diameter, height, and, especially, the variety of available closures. Some closures have, for example, a thread for screwing on primary tubes. Another type of closure is a rubber stopper or cap, which may be removed by a pulling motion. The closures may also differ in their composition. They may be made of rubber, plastic, etc.
Decapping devices that can decap, i.e., remove closures from, all or most of these types of primary tubes have been developed and are available on the market. However, in decapping the tubes, care must be taken not to break the tubes, generally made from glass or plastic, and not to spill any of the sample. There is a further constraint that spills of the sample and any vapors should not be transmitted to other tubes in the instrument which would cause cross-contamination and interfere with the testing and analysis of the samples. Moreover bio-hazard is also an issue as samples are potentially infectious. Thus tubes and closures have to be processed and/or disposed securely.
Once a primary tube has been opened and once a volume of sample has been withdrawn from the tube for processing, it is often desirable to reclose the primary tube, for example, for safety reasons as mentioned above and, in any case, if samples have to be stored for a longer period of time in the event that a further analysis is later required.
One approach is to dispose the original closure after opening the primary tube and to reclose the primary tube with another standard or universal closure. This has the main advantage to make the various steps of opening, pipetting and reclosing more independent from each other. In this way, a primary tube can be opened by a decapping device, moved to a work cell where samples are pipetted and processed and then moved to a recapping device where they are reclosed with a new closure, wherein the process can start over again for another tube before the processing of the previous tube is completed. Another advantage is that recapping is made easier because standard closures of one type are used and if tubes need to be re-opened, decapping is also easier. A disadvantage, however, is that a new closure is introduced for each primary tube, thus increasing processing costs and waste volumes as well as the complexity of the recapping device, since the delivery of a new closure to the recapping device for each tube is needed.
Ideally, the same closure that is removed from a primary tube is used to reclose the same tube. Decapping/recapping devices able to remove a closure of any type and reclose the tube with the same closure after a volume of sample has been withdrawn are also known. This type of device however has the disadvantage that sample processing throughput can be compromised since all steps of opening, pipetting, closing and moving a tube need to be completed before the process can be repeated for another primary tube.
Therefore there is a need for a decapping/recapping device for removing closures from sample tubes and for reclosing the same tubes with the same respective closures in order to increase processing throughput of sample tubes and decrease processing costs.